1. Field of the Invention
The present invention relates to wind cone lighting devices used as evacuation aids for landing aircraft on high rise buildings and other areas where emergency power lighting may be necessary.
2. Description of the Prior Art
The importance of evacuation aids in high rise buildings came to the forefront only in recent times, when in the United States and in other countries disasters have occurred because the fire department ladders could not reach upper floors (generally not above the tenth floor) and helicopters could not land on the tops of the buildings under prevailing wind conditions because of lack of adequate wind direction indication in darkness.
There have, of course, been many lighted wind direction indicators for landing fields advanced in prior years. These are fixed ground installations where adequate power is not a problem and the lighting can be a circle of fixed lights that illuminate a wind cone, or more commonly for wind cones there are four lights, one at each of the major points of the compass, that will provide a ring of light around the wind cone so that its position can readily be seen from the air. A plurality of lights, of course, increases the amount of power consumed and in emergency situations power can be of utmost importance.
For example, lighted wind cones are shown in U.S. Pat. No. 1,776,111. Here a fixed bulb is provided at the top. This type of light does not illuminate the cone well and provides a glare that restricts the appearance of the cone. However, in FIG. 4, a movable contact arm is used for providing signals to a remote wind direction indicator. The movable contact is not used for carrying power to the light. A similar type of device is shown in U.S. Pat. No. 4,201,973 in FIG. 2. In both of these instances, therefore, one of the main supports has to rotate, because the contacts are adjacent the base of the unit. Furthermore, the contacts are used for providing a signal indicating wind direction, and not for illuminating the indicator. A remote wind direction indicator is illuminated with the signal provided by the circular slide contact.
U.S. Pat. No. 4,204,271 shows an illuminated weather vane for mounting on the top of a home or building which has a translucent globe with a light inside that is intended to provide some lighting to the weather vane.
Additionally, in the course of a preliminary search patents of general interest were uncovered and included U.S. Pat. No. 4,046,007 and U.S. Pat. No. 1,946,351. These merely show different types of wind direction indicators.